The water update

Hey! I've figured out how to get the water update to work, so you can now play with maps of a few real locations.

how do I choose a map?

ah, well the current solution is pretty janky, and I will (maybe) fix it to make it more intuitive in the future, but for now, you just enter the file names of the black and white image to the "water texture" field, and the colour image to the "texture" field.

eg: enter [Perth.png] & [Perth_C.png] to get the Perth map

you can add your own maps, they just have to have a pure B&W version depicting where water is and isn't and a colour version to be a texture on the ground, as that's how the system works right now.

I should make a 0.3.5 version to touch up the process and do more gameplay tweaks, but for now this will do.

Thanks,
Mitch